1. Field of the Invention
This invention relates to a method and apparatus for automatically processing elongated photographic films for developing, fixing and washing purposes.
Elongated photographic films as herein used include those photographic films which are usually provided in the length of 100 feet, including the motion picture films of 8mm, 35mm, 70mm and 100mm in width, as well as the screen and non-screen type roll films generally used in X-ray examinations. Also included are relatively short roll films which are used in still photography. It should be understood that the present invention can also be suitably applied to those films which have a length greater than 100 feet, if necessary, should they become popular in the future. Briefly, the "elongated film" may be of any length and width and it may be regarded as a photographic film which has a length greater than its width and which is generally provided in the form of a roll.
2. Description of the Prior Art
In order to process exposed elongated films, it is well known to pass them sequentially through a developing bath, a fixing bath and washing bath in such a manner that they are allowed to stay in each bath for a predetermined period of time, and there have hitherto been introduced a variety of methods and apparatuses for processing elongated films on this known principle. In order to assist the understanding of the present invention, some typical prior art methods and apparatuses are discussed hereinafter.
In one prior-art film processing apparatus, each bath is provided with paired feed rollers and the film is transferred through the respective baths under the guidance of the feed rollers provided therein.
Each treating bath is formed with film guide grooves, for example, of U-shape on opposing side walls thereof for engagement with longitudinal side edges portions of the film under treatment so that the film is guided along the guide grooves into and out of the treating solution in each bath. In certain cases, paired guide rolls are provided at suitable positions in the bath to cooperate with the guide grooves in moving the film into and out of the treating solution.
The overhead paired film feed rollers are located above a number of treating baths which are positioned one after another along the path of travel of the film. It is the general practice to provide vertically movable rollers between the respective pairs of the film feed rollers to immerse the film forcibly in the treating solution in a looped form with the downward movement of the roller.
There have been proposed and put in use many other elongated film processing methods and apparatus but they have a common drawback in that it is necessary to provide a film guiding mechanism integrally with the treating bath or a film guiding mechanism which is adapted to be immersed in the treating solution together with the film. This obviously requires a treating bath of a relatively large size and therefore results in increased consumption of the treating solution. Furthermore, the immersion of the film guide mechanism gives rise to various troubles.
In the prior-art film processing apparatus where the film guide mechanism is provided as an integral part of the treating bath, it is difficult to construct the film feed mechanism so as to be separable from the treating bath and free from the treating solution, so that the processing apparatus as a whole has to be fabricated in a large size which requires increased maintenance work.